Rotary cutter for leather-work



No. 6l3,6l8. Patented Nov. I, I898.

E. GHILDS ROTARY CUTTER FOR LEATHER WORK.

(Application Aug. 27, 1897.)

(N0 Model.)

z l HIM/:7

UNrTnn STATES PATENT Oriana.

EUGENE OI-IILDS, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE TRIMONT MANUFACTURING COMPANY, OF PORTLAND, MAINE.

ROTARY CUTTER FOR LEATHER-WORK.

SPECIFICATION forming part of Letters Patent No. 613,618, dated November 1, 1898.

Application filed August 27, 1897. Serial No. 649.720. (No model.)

To aZl whom it may concern:

Be it known that I, EUGENE OHILDs, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Rotary Outters for Leather-fork, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings representing like parts. I

This invention has for its object to improve that class of rotary cutter having concavoconvex blades in cross-section, said blades being held at their side edges between two disks or circular plates, which are forced one to-' ward the other to thereby clamp the said blades firmly and hold them in fixed position during the action of the rotary cutter. A thin blade cuts better and operates more satisfactorily than a thick blade, and efforts have been made in this class of cutters to reduce the thickness of the blades, but in such attempts the blade has been made thinner throughout from its cutting edge to its heel; but said blades when so reduced to the best thickness for'easy trimming have been found to lack suitable strength, for they, under the action of the disks, which clamp them firmly in working position, buckle or bend longitudinally, and this tendency to buckle or break is increased by the cutting strains to which the blades are subjected. I have attempted to obviate this trouble, and I have overcome these objections and have produced a novel blade, said blade having its heel thick enough for some distance toward the cutting edge of the blade to avoid being bent by any strain exerted on the blade in clamping it firmly in the head, the remainder of the blade from its thickened heel toward its cutting edge being cut out at the inner or concaved side of the blade to thereby give to the cutting part of the blade greater thinness than has been heretofore practical.

Figure 1., in front elevation, shows a rotary cutter embodying this invention. Fig. 2 is a partial section of the same in the dotted line :0, Fig. 1, the section being taken through the thicker heel part of one blade and the thinner cutting part of another blade. Fig. 3

shows a face View of the inner disk or plate of the head. Fig. 4 shows a blade in perspective, the view looking at its inner side. Fig. 5 shows an inner side View of the outer disk, or, as it is sometimes called, the follower; and Fig. 6 is a section in the line x taken through a blade.

The rotary cutter is composed, essentially, of three like blades A, each, as shown, having at its opposite side edges eccentric projecting lips or fins a a, the lip or fin a entering a groove or notch in the plate b, while the lip or fin a is made to enter a notch or groove 0 in the disk, plate, or follower c, the latter being forced toward the plate I) by a suitable nut or bolt 6, it in practice being suitably threaded to be screwed into a threaded part of the rotating shaft e. These blades are concavo-convex both in longitudinal and in cross-section, and each side rib of each blade enters its own eccentric groove and meets a suitable stop f. These devices, including the blades, excepting in the particular shapes of the blades to be hereinafter described and claimed, are and may be all substantially as shown in United States Patent No. 354,442, dated December 14, 1886.

In this particular invention the blades A (see Figs. 2 and4) are made thicker at their heels 2, the thick part extending entirely across the blade from lip to lip' and in the direction of the length of the blade sufficiently far to afford for said blade a strength or stiff- ,ness which will preclude buckling or bending of the blade longitudinally, due to the clamping pressure on the sides of the blade between the disk or plates 1) c, and also resist the strains to which the blades are subjected in operation. At, however, a short distance from this thickened heel I have reduced the thickness of the blade by removing a part of the stock from its inner side, said reduction in thickness being carried'out to the cutting edge, said reduction in thickness not only providing a lighter-weight blade which is manifested in the running of the cutter, but also enabling the thickness of the blade to be so greatly reduced as to make a comparatively thin blade, one that cuts easily and yet has ample stiifness to stand up to its work, this being due chiefly to its thickened heel.

The thin part of the blade from the inner end 4: of the thickened heel to the bevel 5 of the cutting edge is of substantially the same thickness, this uniformity in thickness being gained by the action of a cutting-tool while the blade is held in a novel chuck made the subject of United States application, Serial No. 653,3a1, filed September 28, 1807, said cutting-tool being under the control of a pat tern-surface.

My improved blade Weighs less and cuts the leather better and more satisfactorily than the ordinary thick blade. The thinner the blade the easier it cuts and the quicker it may be ground, and so, also, the thinner the blade the more uniformly it may be tempered.

Having described my invention, what I claim, and desire to secure by Letters Patent, 1s

A cutter-blade for heel-trimming, it being composed of a forging convexed at its outer face both in the direction of its length and breadth, and provided at each side edge with a fin, said cutter-blade having its heel end thickened from one to its other side edge to afford the strength required to enable the blade in operation to be firmly clamped and held by its fins and not bend longitudinally, said blade at its interior from said thickened heel to its sharpened cutting end being cut away to thereby reduce the thickness of the blade from the heel to its cutting edge leaving an interior surface concaved both in the direction of the length and Width of the blade, the thinning of said blade from its thickened heel toward its cutting edge e11- hancing the cutting qualities of the blade, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' EUGENE CHILDS.

\Vitnesses:

Gno. W. GREGORY, FREDERICK L. EMERY. 

